Vitamin B12: Some chlorella varieties may also contain vitamin B12, but more studies are needed .

Iron and vitamin C: Chlorella can be a good source of iron. Depending on the supplement, it may provide anywhere from 6–40% of your daily need. It’s also an excellent source of vitamin C, which helps you absorb iron .

Other antioxidants: These tiny green cells provide a wide range of antioxidants .

2. Binds to Heavy Metals, Aiding Detox

Chlorella has gotten some buzz for its ability to help the body “detox.”

In fact, animal studies indicate that it’s effective at helping remove heavy metals and other harmful compounds from the body .

Heavy metals include some elements that are essential in small amounts, such as iron and copper, but these and other heavy metals like cadmium and lead can be toxic in larger amounts.

While it’s rare for people to have dangerous levels of heavy metals in their system, people can get exposed to heavy metals through pollution or certain jobs such as mining .

In animals, algae, including chlorella, has been found to weaken the heavy metal toxicity of the liver, brain and kidneys .

Furthermore, chlorella has been shown to help lower the amount of other harmful chemicals that are sometimes found in food. One of these is dioxin, a hormone disruptor that can contaminate animals in the food supply .

Based on this evidence, it seems that chlorella could help enhance your body’s natural ability to clear toxins.

Summary: Chlorella may help the body detox by binding to heavy metals and other toxins.

3. Could Enhance Your Immune System

Your immune system helps keep you healthy by fighting off infections.

It’s a complex system made up of multiple mechanisms and cells that get into gear when an invader enters your body.

Chlorella has been found to enhance the immune response in both animal and human studies, although the evidence so far is limited.

In one small study, men produced more antibodies when taking chlorella than when they took a placebo. Antibodies help fight foreign invaders in your body, meaning this finding is quite promising .

Nevertheless, findings have been mixed, with some studies showing little to no effect.

For instance, one study found that chlorella supplements enhanced immune function in participants aged 50–55, but not those over 55 .

So it’s possible that chlorella may have immune-boosting effects in some populations and age groups, but not in all. More and larger-scale studies are needed.

Summary: Chlorella may bolster immune function by increasing the activity of various parts of the immune system.

4. May Help Improve Cholesterol

Several studies have suggested that chlorella supplements may help lower cholesterol .

Specifically, several studies have shown that taking 5–10 grams of chlorella daily lowered total and LDL cholesterol and triglycerides in people with high blood pressure and/or slightly elevated cholesterol .

Chlorella’s content of the following may help improve blood lipid levels:

Niacin: A B vitamin known to lower cholesterol .

Fiber: A cholesterol-lowering agent .

Carotenoids: Have been shown to naturally lower cholesterol .

Antioxidants: Help prevent the oxidation of LDL cholesterol, which is known to contribute to heart disease .

Summary: The nutrients found in chlorella, including niacin, fiber, carotenoids and antioxidants, may help lower your cholesterol levels.

5. Acts as an Antioxidant

Chlorella contains several compounds that are considered antioxidants, including chlorophyll, vitamin C, beta-carotene, lycopene and lutein .

These antioxidants can help fight many chronic diseases .

Some of these antioxidants seem to reduce the production of advanced glycation end products (AGEs), which drive many of the complications of diabetes .

In animals and lab studies, chlorella has interfered with the way genes age .

8. May Help Manage Respiratory Diseases

Chlorella has some components that can help reduce inflammation, including its many antioxidants .

One study found that chlorella supplements improved antioxidant status in COPD patients, but that didn’t translate into any improvements in breathing capability .

More studies are needed to determine its true effect on respiratory conditions, but chlorella might help with inflammation.

Summary: The antioxidants in chlorella may have anti-inflammatory effects, which can possibly improve asthma and other respiratory diseases.

9. May Enhance Aerobic Endurance

Only one study has looked at chlorella’s effect on aerobic endurance, but it showed a positive effect.

Researchers gave a group of young adults six grams of chlorella or a placebo daily for four weeks.

At the end of the study, the chlorella group showed a significantly improved ability to saturate their lungs with oxygen, which is a measure of endurance. The placebo group did not experience any changes in endurance .

This effect may be due to chlorella’s branched-chain amino acid content.

Branched-chain amino acids are a collection of three amino acids that have been found to improve aerobic performance in various studies .

Summary: Chlorella may improve your aerobic performance, although scientific support for this benefit is limited.

Other Potential Benefits

Many other possible benefits have been proposed, but there’s little research to support these claims.

Here are some of the main health claims:

Promotes eye health: Chlorella contains lutein and zeaxanthin, two carotenoids that protect the eye and lower the risk of macular degeneration .

Supports liver health: Chlorella supplements have been shown to improve markers of liver health in people with liver disease. However, it’s not clear whether there’s a benefit for healthy people .

Improved digestion: Many sources claim chlorella eases digestion and reduces bloating. However, no studies have assessed these proposed benefits.

Relieves PMS: Anecdotal evidence says that chlorella can relieve symptoms of premenstrual syndrome (PMS). It could be a stretch, but chlorella contains calcium and B-vitamins, both of which have been shown to reduce PMS .

While there’s no specific research to back up these claims, chlorella’s nutrient content could, in theory, have these benefits .

Summary: Chlorella has been claimed to improve energy levels, liver health, digestion and symptoms of PMS. Nevertheless, scientific evidence is currently lacking to directly support these claims.

Potential Concerns

Chlorella has been deemed “generally recognized as safe” by the FDA .

However, there are a few things to keep in mind when considering chlorella supplements:

Possible side effects: Some people have experienced nausea and abdominal discomfort .

Lack of regulation: Some countries, including the US, do not regulate supplements, and you can’t be sure you’re getting what the label says.

Inconsistent products: The nutrition content of chlorella supplements may vary, depending on the algae species, growing conditions and processing .

Immune effects: Since chlorella affects the immune system, it may not be appropriate for people with immunodeficiency or on immune system medications.

Furthermore, it’s important to keep in mind that dietary supplements may interact with some medications.

While chlorella is generally recognized as safe and few side effects have been reported, it might not be appropriate for everyone.